Display device for displaying simultaneously a plurality of symbols arranged in juxtaposed relation in one line

ABSTRACT

Display device for displaying simultaneously a plurality of alpha-numeric and other special symbols arranged in juxtaposed relation in one line wherein said symbols are displayed by a plurality of horizontal scanning lines which are vertically deflected by a few fundamental waveforms and the phosphor screen of a CRT is excited to luminesence at a required portion or portions of said deflected waveform.

United States Patent Inventor Terumlchi Yokoyama Tokyo, Japan Appl. No. 841,795

Filed July 15, 1969 Patented Dec. 28, 1971 Assignee Kabushiki Kaisha Ricoh Tokyo, Japan Priority July 15, 1968 Japan 43/49041 DISPLAY DEVICE FOR DISPLAYING SIMULTANEOUSLY A PLURALITY OF SYMBOLS ARRANGED IN JUXTAPOSED RELATION IN ONE LINE 7 Claims, 4 Drawing Figs.

U.S. C1 340/324 A, 315/18, 315/25 Int. Cl. G061 3/ 14 Field of Searc 340/324 A; 315/13 R, 18, 19,25

[56] References Cited UNITED STATES PATENTS 2,763,808 9/1956 Lurcott, Jr 315/25 2,522,380 9/1950 Kline et al.... 315/13 2,978,608 4/1961 Gaffney,Jr.. 315/13 3,342,936 9/1967 Ascoli et al. 340/324 3,524,998 8/1970 Gilbert 340/324 Primary Examiner-John W. Caldwell, Jr. Assistant Examiner-Marshall M. Curtis Attorney-Burgess, Ryan and Hicks Patented Dec. 28, 1971 3,631,456

3 Sheets-Sheet 3 I 2 I S BUFFER REGISTER DECODER 7 S I I wAvE FORM BRIGHT LINE OR O R I MAIN FOCUS CLOCK cONsTANT COIL PULSE CURRENT RATOR Z" 5 S wAvE TORM wAvE FORM SHAPING sELEcTION AMP cIRGuIT MATRIX 5 I BRIGHT LINE BRIGHT LINE BRIGHTNESS -TIMING PuLsE SELECTION GENERATOR MATRIX I I 9 I3 ISO SWEEP 44.5 AMP 'INVENTOR 7Z'RuM/cH/ VO/( VAMA fl w W. w/ f/ZQQ ATTORNEYS DISPLAY DEVICE FOR DISPLAYING SIMULTANEOUSLY A PLURALITY OF SYMBOLS ARRANGED IN JUXTAPOSED RELATION IN ONE LINE BACKGROUND OF THE INVENTION The present invention relates to a character-display device and more particularly to an improvement of a character disvplay cathode-ray tube which for example may be used for electrophotographic apparatus.

There has been proposed a character-display device of the type in which a character is displayed by the combinations or synthesis of the horizontal and vertical strokes. The device of the type requires the circuits for str'oking in .the X and Y directions respectively so that it becomes complicated inconstruction and expensive in cost.

It is one of the objects of the present invention to provide .a character-display device having the minimum number of stroking" circuits. I

Another object of the present invention is to provide a character-display device of the type in which stroking"is effected only in the vertical direction while the horizontal stroke is a scanning line.

A further object of the present invention is to provide a character-display device having simple waveforms for vertical deflection.

A still further object of thepresent invention is toprovide a character-display device inexpensive tomanu'facture.

SUMMARY OF THE INVENTION Thepresent'invention relates to a character-display device of a cathode-ray tube which may be used for example for printing by electrophotographydt is to be understood that'the term character" implies not only alpha-numeric symbols but also other symbols.

According to the present invention, each of the horizontal scanning beams is deflected vertically in accordance with a few fundamental waveforms and the screen of a cathode-ray tube is excited to luminescence at a requiredportion orportions of the deflected waveform so that a plurality. of symbols arranged in juxtaposed relation in one line'may'be simultaneously displayed. A plurality of horizontal scanning beams is required for each line of the display, and the beams are sequentially generated. Said fundamental waveforms include a sinusoidal waveform, another sinusoidal waveform 'whose frequency is a multipleof the frequency of said firstmentioned sinusoidal waveform, a triangularly shaped waveform and another triangular waveform having a frequency which is a multiple of the frequency of said first mentioned triangular waveform.

According to one embodiment of the present invention, a

plurality of symbols arranged in juxtaposed relation in one line may be displayed by four horizontal scanning lines which are deflected vertically to a-predetermined extent by the above described fundamental waveforms. The brightness grid of the cathode-ray tube is controlled atarequired portion or portions of the deflected-waveform so that the screen of the cathode-ray tube is excited to luminescence. The luminescence portions of .the screenare combinedin four scannings so that the symbols are displayed and then printed if required.

The above and other objects, features and advantages of the present invention will become more apparent from the following description of one illustrative embodiment thereof .with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS FIG. 1 is an illustration of the fundamental wavefonns used in the present invention;

FIG. 2 illustrates symbols to be displayed by the synthesis of various portions ofsaid fundamental waveforms;

FIG. 3 illustrates the symbol synthesis process; and FIG. 4 is a block diagram of one embodiment of the device of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1 illustrating the fundamental waveforms for effecting the vertical deflection of the horizontal scanning electron beam, a designates a sinusoidal-wave; b, a sinusoidal wave having a'frequency three times as high as that wave a; c, atriangular wave; and d, a triangular wave c. All of the above waves are in synchronism with the clock pulses (for example, 30kc.) designated by e in FIG. 1. Each clock pulse is generated so as to divide the width of one alpha-numeric symbol into a unit width, the width of one symbol in the embodiment shown in FIG. 1 being dividedinto six unit widths. The spacing between :the pulses is the'minimum unit of bright line (which should beztaken in this specification to mean that during this minimum bright'line unit ,the phosphor screen of the cathode-raytube is excited to'luminescence by electron bom- 'bardment).

FIG. 2 illustrates alpha-numeric symbols constructed or synthesized by use of the fundamental waves shown in FIG. I, the symbols including the Japanese characters, numerals, alphabets and special symbols. .Each symbol may be constructed by four strokes atxthemost according to the present invention. That is, -the-symbols maybe displayed in side-byside relation by-four-horizontal scanning lines that is by four horizontal scanning operations.

FIG. 3 is for explanation'how the three symbols Japanese .character 7, 3 and A aresynthesized orconstructed according to thepresent invention, and also illustrates the waves and bright lines selected for constructingthe abovethree symbols. The selected waves are indicated by the dotted lines while the bright line (to excite the screen of CRT to luminescence),-bythe solid lines. Therefore, it'willbe seen that the solid lines are strokes-for constructing a symbol. SCI, 8C2, 'SCSand SC4 designatethe timing for horizontal scanning and as described hereinabove, each symbol may, be constructed by four horizontal scannings at the most.

The waves and the bright line timing selected. for, constructing the above three symbols are shown in the following table:

Waves Selected =L-='vertical level, N representing the height of levels. L L,, L L an'd' L, which divide the height of the symbol into four subheights;

Sin T=the wavea in FIG-l; Sin3T=the wave -b in FIG. I; Tri T=the-wave c in FIG. I;

("T implies time) h and ;and V4 of the height of the .wave;

- =inverted waves;

l to 6 =six divided section of one symbol from left to right,

1 that is one unit width of the width. of onesymbol. as

described above. 7

FIG.- 4- illustrate. a block diagram of the. present invention.

:Reference. numeral 1 designates a buffer. register having a suitable number of. stages forexample stages'each having :seven bits (the total of 128 symbols being represented) and of the type of a shift register which is shifted once every eight main clock pulses. A decoder 2 receives an input signal consisting of seven bits and identifies in its matrix and derives an output signal representing one of 128 symbols. A main clock pulse generator 3 generates pulses of for example 30kc. which may be used as unit bright line timing pulses synchronizing pulses for the waveform shaping circuit, shifting pulse for the buffer register, etc. A waveform shaping circuit 4 comprises four oscillators for generating four fundamental waves of Sin T, Sin 3T, Tri T and Tri 3T and a matrix for determining the levels L L 1.. and L and the heights of A, h and thereby shaping all of the waveforms required for reconstructing a symbol. A bright line timing pulse generator 5 generates various combinations of bright line timing pulses by an octal counter which counts the main timing clock pulses so that the time for exciting the faceplate to luminescence for constructing all of the symbols may be determined. A waveform OR-circuit 6 is for combining into one output signal the signals ofthe decoder 2 which select the same waveforms in each scanning. It is noted that from the decoder 2 are generated the output signals the number of which corresponds with that of the strokes for constructing one symbol. A bright line OR-circuit 7 is similar in function to the waveform OR-circuit. That is, the circuit 7 serves to combine into one output signal the input signals which select the same bright line. A waveform selection matrix 8 selects a suitable waveform generated by the waveform shaping circuit 4 depending upon the output from the waveform OR-circuit 6. A bright line selection matrix 9 selects the bright line timing pulses from the bright line generator 5 depending upon the output from the bright line OR-circuit 7. Reference numeral 10 designates a sweep pulse generator (44.5c.); 11, a constant current source for a focusing coil; l2, l3 and 14 are amplifiers, the output of the amplifier 12 being applied to the vertical deflection electrodes or coil, the output of the amplifier 13, to the brightness grid and the output of the amplifier 14, to the horizontal deflection coil or electrodes.

Next the mode of operation of the device of the present invention will be described.

a. The information for one line is applied to the buffer register and circulated in the register until four scannings (for the preceding line) are accomplished in CRT.

b. Upon initiation of the first horizontal scanning, the information in the buffer register is applied to the decoder so that the waveforms and bright lines for one symbol are selected. Upon completion of the first horizontal scanning, the buffer register is reset to its initial state. Four horizontal scannings are effected in four circulations in the buffer register.

c. The waveform pulses selected at each of four horizontal scannings are applied to the vertical deflection electrodes or coil of CRT while the selected bright line pulses, to the brightness grid. The horizontal scanning pulses which are tooth-shaped are applied to the horizontal deflection electrodes or coil. Thus, by four horizontal scannings, the symbols in one line are displayed upon the faceplate of CRT, and may be printed by a printing mechanism.

6. Upon completion of the display of said one line, the information for the next line is applied to the buffer register and the operations described in (a), (b) and (c) are cycled.

From the foregoing, it will be seen that according to the present invention only a small number of fundamental waveforms (only four in the embodiment described above) are required for constructing the symbols so that the indicating device is very simple in construction. Furthermore, the horizontal scanning is made a plurality of times (four in the embodiment described above) by the triangularly shaped waves so that it is possible to display a plurality of symbols in one line, that is in side-by-side or juxtaposed relation within a very short time. As illustrated in FIG. 2, various alpha-numeric symbols and other symbols may be displayed without deleteriously affecting the normal forms of the symbols.

It will be understood that the fundamental waveforms are not limited to those described hereinaboye and illustrated in the accompanying drawings and that the sinusoidal waves may be replaced with the circular or trapezoidal waveforms.

I claim:

1. A character-display device for displaying simultaneously a plurality of symbols arranged in juxtaposed relation in one line comprising a cathode-ray tube having a faceplate;

means for sequentially generating a plurality of horizontal scanning beams for displaying symbols upon the faceplate of said cathode-ray tube;

fundamental waveform generating means for producing a plurality of fundamental waveforms responsive to input data;

means for vertically deflecting the beam during each of said sequentially generated horizontal scan responsive to said fundamental waveform generating means; and

blanking means for selectively illuminating said faceplate at selected portions of said deflecting waveforms so that said symbols are constructed of segments corresponding to portions of said deflecting waveforms.

2. A character-display device as claimed in claim 1, wherein said fundamental waveform generating means generates a first sinusoidal waveform, a second sinusoidal waveform having a frequency which is a multiple of the frequency of said first sinusoidal waveform, a first triangular waveform and a second triangular waveform having a frequency which is a multiple of the frequency of said first triangular waveform.

3. A character-display device as claimed in claim 1, wherein said faceplate is divided into a plurality of horizontal segments, said blanking means energizing selected ones of said horizontal segments as said beam horizontally scans said faceplate.

4. A character-display device as claimed in claim 1, wherein each of said symbols is divided into a plurality of horizontal segments, said blanking means energizing selected ones of said segments on said faceplate as said beam horizontally scans said faceplate to construct said symbols.

5. A character-display device as claimed in claim 1, wherein said horizontal scanning beam sequentially scans said faceplate at successively different vertical levels of said faceplate.

6. A character-display device as claimed in claim 1, comprising a decoder wherein said fundamental waveform generating means comprises a matrix, said symbols to be displayed being supplied to said decoder, said decoder being connected to said matrix for selecting at least one of said fundamental waveforms.

7. A character-display device as claimed in claim 6, wherein said selective blanking means comprises a bright line selection matrix being connected to said decoder and being responsive to said decoder for selectively illuminating said faceplate.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3I63lI456 Dated December 1971 Inventor(x) Terum-i chi T kvama It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 7, before "c" insert having a frequency three times as high'as the triangular wave Signed and sealed this 11th day of July 1972.

(SEAL) Attest:

EDWARD I LFLETC HER,JR. ROBERT GOTTSCHALK At testing Officer Commissioner of Patents Case 1770-132 FORM PO-105O (10-69) USCQMIWDC 6o376 p69 us. GOVERNMENT PRINTING OFFICE mes o-ass-au UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 316311456 Dated 7 December 1971 Inventor (x) Ternmi chi Tokvama It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 2, line 7, before "c" insert having a frequency three times as high as the triangular wave Signed and sealed this 11th day or July 1972.

( SEAL) Attest:

WAR D M. FL ETC HER, JR v ROBERT GOT TSCHAL K Attesting Officer Commissioner of Patents Case 1770-132 FORM PC4050 (10459) USCOMM-DC scam-P69 a U.S. GQVERNMENT PRINTING OFFCE! I969 3$6'334 

1. A character-display device for displaying simultaneously a plurality of symbols arranged in juxtaposed relation in one line comprising a cathode-ray tube having a faceplate; means for sequentially generating a plurality of horizontal scanning beams for displaying symbols upon the faceplate of said cathode-ray tube; fundamental waveform generating means for producing a plurality of fundamental waveforms responsive to input data; means for vertically deflecting the beam during each of said sequentially generated horizontal scan responsive to said fundamental waveform generating means; and blanking means for selectively illuminating said faceplate at selected portions of said deflecting waveforms so that said symbols are constructed of segments corresponding to portions of said deflecting waveforms.
 2. A character-display device as claimed in claim 1, wherein said fundamental waveform generating means generates a first sinusoidal waveform, a second sinusoidal waveform having a frequency which is a multiple of the frequency of said first sinusoidal waveform, a first triangular waveform and a second triangular waveform having a frequency which is a multiple of the frequency of said first triangular waveform.
 3. A character-display device as claimed in claim 1, wherein said faceplate is divided into a plurality of horizontal segments, said blanking means energizing selected ones of said horizontal segments as said beam horizontally scans said faceplate.
 4. A character-display device as claimed in claim 1, wherein each of said symbols is divided into a plurality of horizontal segments, said blanking means energizing selected ones of said segments on said faceplate as said beam horizontally scans said faceplate to construct said symbols.
 5. A character-display device as claimed in claim 1, wherein said horizontal scanning beam sequentially scans said faceplate at successively different vertical levels of said faceplate.
 6. A character-display device as claimed in claim 1, comprising a decoder wherein said fundamental waveform generating means comprises a matrix, said symbols to be displayed being supplied to said decoder, said decoder being connected to said matrix for selecting at least one of said fundamental waveforms.
 7. A character-display device as claimed in claim 6, wherein said selective blanking means comprises a bright line selection matrix being connected to said decoder and being responsive to said decoder for selectively illuminating said faceplate. 